The Data and Statistical Analysis Core will fully support the study design, data entry, data management, programming and statistical and data analysis for all six projects nested within the center. Proper and efficient data processing procedures and management are essential to ensure the quality of data used in analysis. Inferences and conclusions from medical and health services research projects rest largely on data and statistical analysis. The missions of the Core are to provide strong statistical foundations and analytical methodologies pertinent to each project and research question, to resolve particular statistical issues arising in each project and to perform data management, data checking, programming and statistical analysis for each individual project. The Core will regularly assess analytic needs across projects and will make allocation recommendations to the Program Project leadership when needed. Security and confidentiality for all data are the responsibility of the core. All data collected will be maintained according to the guidelines of OMB Circular A-130, and the core will ensure that every site will follow the data security procedures established by the core. These procedures will be incorporated into well-defined protocols. The core will facilitate the sharing of the data and the integration of existing data sets such as MEPS, HCSUS and other AHRQ data. The Core will be responsible for selecting and implementing proper statistical methodologies used in each project and each research question within a project, and also responsible for interpreting the results from statistical/data analysis and modeling. The statisticians in the core will help in translating the statistical findings into clinical, public health and social science interpretations. The Core will coordinate and balance the needs and resources for programming and statistical support across the projects. The Core will seek to enhance and improve those statistical methods that are found to be particularly important and useful to the center projects and will develop new statistical methods that will facilitate analysis of data from the complex survey designs. The Core will also interact with other cores within the Program Project to resolve any statistical issues they may have or to consult with them about questions in their expertise.